DNA damage and repair proteins in cellular response to sulfur mustard in Iranian veterans more than two decades after exposure

Delayed effects of sulfur mustard (SM) exposure on the levels of five important damage/repair proteins were investigated in 40 SM-exposed veterans of Iran-Iraq war and 35 unexposed controls. A major DNA damage biomarker protein – phosphorylated H2AX – along with four DNA repair proteins in cell response to the genome damage MRE11, NBS1, RAD51, and XPA were evaluated in blood lymphocytes from the veterans and controls using western blotting. Mean levels of XPA, MRE11, RAD51 and NBS1 were lower in SM-exposed patients and the decrease in NBS1 was significant. Even though the raised level of phosphor-H2AX in SM-poisoned group compared to the controls was not significant it was consistent with DNA damage findings confirming the severity of damage to the DNA after exposure to SM. There were correlations between the values of RAD51 and NBS1 proteins as well as XPA and MRE11 proteins. More than two decades after exposure to SM, there is still evidences of DNA damage as well as impaired repair mechanisms in cells of exposed individuals. Such disorders in cellular level may contribute to long term health problems of the SM veterans

Deoxyribonucleic acid damage in Iranian veterans 25 years after wartime exposure to sulfur mustard

• Background: More than 100,000 Iranian veterans and civilians still suffer from various long-term complications due to their exposure to sulfur mustard (SM) during the Iran–Iraq war in 1983–88. The aim of the study was to investigate DNA damage of SM in veterans who were exposed to SM, 23–27 years prior to this study. • Materials and Methods: Blood samples were obtained from the veterans and healthy volunteers as negative controls. Lymphocytes were isolated from blood samples and DNA breaks were measured using single-cell microgel electrophoresis technique under alkaline conditions (comet assay). Single cells were analyzed with “Tri Tek Comet Score version 1.5” software and DNA break was measured based on the percentage of tail DNA alone, or in the presence of H2O2 (25 μM) as a positive control. • Results: A total of 25 SM exposed male veterans and 25 male healthy volunteers with similar ages (44.66 ± 6.2 and 42.12 ± 5.75 years, respectively) were studied. Percentage of the lymphocyte DNA damage was significantly (p < 0.01) higher in the SM-exposed individuals than in the controls (6.47 ± 0.52 and 1.31 ± 0.35, respectively). Percentages of DNA damage in the different age groups of 35–39, 40–44, 45–49, and 50–54 years in SM-exposed veterans (5.48 ± 0.17, 6.7 3 ± 1.58, 6.42 ± 0.22, and 7.27 ± 0.38, respectively) were all significantly (p < 0.05) higher than the controls (1.18 ± 0.25, 1.53 ± 0.22, 1.27 ± 0.20, and 1.42 ± 0.10, respectively). The lymphocytes incubated with H2O2 had much higher DNA damage as expected. The average of tail DNA is 42.12 ± 2.75% for control cells + H2O2 and 18.48 ± 2.14% for patients cells + H2O2; P < 0.001. • Conclusion: SM exposure of the veterans revealed DNA damage as judged by the comet assay

Telomere shortening associated with increased levels of oxidative stress in sulfur mustard-exposed Iranian veterans

Sulfur Mustard (SM) is the most widely used chemical weapon. It was used in World War 1 and in the more recent Iran-Iraq conflict. Genetic toxicity and DNA alkylation effects of SM in molecular and animal experiments are well documented. In this study, lymphocytic telomere lengths and serum levels of isoprostane F2α were measured using q-PCR and enzyme immunoassay-based methods in 40 Iranian veterans who had been exposed to SM between 1983-88 and 40 non-exposed healthy volunteers. The relative telomere length in SM-exposed individuals was found to be significantly shorter than the non-exposed individuals. In addition, the level of 8-isoprostane F2α was significantly higher in the SM-exposed group compared to controls. Oxidative stress can be caused by defective antioxidant responses following gene mutations or altered activities of antioxidant enzymes. Chronic respiratory diseases and infections may also increaseoxidative stress. The novel finding of this study was a the identification of ‘premature ageing phenotype’. More specifically, telomere shortening which occurs naturally with aging is accelerated in SM-exposed individuals. Oxidative stress, mutations in DNA repair genes and epimutaions may be among the major mechanisms of telomere attrition. These findings may help for a novel therapeutic strategy by telomere elongation or for validation of an exposure biomarker for SM toxicity

Study of aqueous extract of three medicinal plants on cell membrane–permeabilizing and their surface properties

The aim of this study was to evaluate the effect of aqueous extract of three medicinal plants, Artemisia dracunculus L, Cuminum cyminum L and Heracleum persicum Desf, which contain saponins on biological membrane. Also in this study, some of their physicochemical properties were studied. At the first step, the aqueous extract of the plants were prepared, using maceration and then the extracts were lyophilized. 0.2 ml of RBC was added to 0.2 ml of different concentrations of each extract in McIvan’s buffer, and then incubated in two different times and temperatures. The absorbance of the samples was determined by UV spectrophotometer. Among the three studied extracts, A. dracunculus L showed the highest hemolytic effect and the Heracleum persicum Desf showed the lowest one. The values of emulsification Index (E24) and foam formation activity (Fh) showed for each extract the properties of surface activity. Regarding the results of this study, when considering the health of consumer, the use of aqueous extract of H. persicum Desf, with low hemolytic effect is preferred in pharmaceutical preparation. But if the hemolytic effect were considered, the use of aqueous extract of A. dracunculus L, with great hemolythc effect in comparison to the two other extract, is preferred

Evaluating the toxicity of permeability enhanchers of polyethylene glycol brij ethers surfactants group on cellular membranes and some of their physicochemical properties

The aim of this study is to evaluate the effect of polyethylene glycol brij ethers surfactants group on red blood cells as a model for biological membranes. Also in this study, physicochemical properties including emulsification index (E24), foam producing activity (Fh) and critical micelle concentration (cmc) were studied. Surfactant solutions were prepared in McIvan’s buffer in specific concentrations. 0.2 ml of red blood cells (RBC) was mixed with 0.2 ml of each surfactant solution. The four surfactant solutions had each been incubated differently at two different temperatures for three different times. Each test was done six times. The results were presented as mean absorbance ± the standard deviation. E24, Fh and cmc were also determined for each surfactant solution. All of the surfactant solutions showed hemolytic activity. In comparison with the four studied surfactants, brij 56 had the highest hemolytic effect and brij 72 the lowest. The values of E24 and Fh had good correlation with hydrophilic-lipophilic balance values. According to the results of this study, brijs should be used at concentrations lower than cmc in formulations. Also, according to the results, the use of brijs with low hemolytic effect such as brij 72, is preferred in pharmaceutical preparations

Investigation of cellular hydrophobicity and surface activity effects of biosynthesed biosurfactant from broth media of PTCC 1561

Biosurfactants as surface active molecules that are synthesized by microorganisms. These substances include many advantages in comparison with chemical surfactants. For instance they have lower toxicity, higher biodegradability, better environmental compatibility, higher foaming activity, and specific activity at extreme temperatures, pH ranges, and the ability to be synthesized from renewable feed stocksin. In this study, the production of biosurfactant, produced by PTCC 1561 was studied. This bactrium was grown in a nutrient broth medium and the production of biosurfactant was evaluated by the surface tension and emulisification index (E24), each 24 h. The production of biosurfactant was studied in different conditions, including time of incubation, temperature, aeration rate and presence of several additives containing mineral salts and hydrocarbons. Finally, the optimum condition for production of the biosurfactant was determined and the biosurfactant identity was investigated using chemical and spectroscopy methods. The maximum biosurfactant production by Pseudomonas aeruginosa PTCC 1561, was exhibited when it was grown in Brain Hearth Broth medium containing Fecl3, ZnSO4, FeSO4, starch and olive oil incubated in a 200 rpm shaker incubator at 37°C for 24 h . The structure of produced biosurfactant sugar-lipid was confirmed by chemical and spectroscopy methods

Antitumor and antibacterial activity of four fractions from Heracleum persicum Desf. and Cinnamomum zeylanicum Blume

At the present study tumor inhibition and antibacterial activity of the essential oils of Heracleum persicum and Cinnamomum zeylanicum was investigated. Methanol and petroleum ether were extracted from C. zeylanicum by potato disk method. These fractions showed cytotoxic effects in brine shrimp lethality assay (BSL). The authors found both H. persicum (57.16%) and C. zeylanicum (72.90%) had inhibition effects on Agrobacterium tumefaciens which induced crown gall tumor on potato disk. These oils also exhibited antitumor activity where IC50 was applied and the values were 2.24 and 1.20 mg/mL, respectively, for H. persicum and C. zeylanicum. C. zeylanicum also inhibited the growth of all tested Gram- positive and Gram-negative strains. In all, the findings of the present study completely correspond to the results obtained in brine shrimp lethality